Business forms, paper, and many other products are conventionally shipped and stored in two piece cartons having a carton body and a top, both of cardboard. Since it is highly desirable for the carton lids to be reused in such cartons, the carton lid is typically secured to the carton body by plastic straps. This is an expensive procedure, however, since there is a substantial investment in automatic strapping equipment, since the plastic straps are relatively expensive, and since there are significant maintenance costs associated with the automatic strappers. Therefore, it is highly desirable to provide a carton with a reusable lid that may be shipped without plastic strapping, while still securely maintaining the carton contents.
Further, in conventional corrugated cartons, during shipping and handling varying amounts of weight and momentum are applied to the carton. This has led many users of cartons to build higher cost and higher strength corrugated paperboard cartons in order to maintain a rigid box of unchanging depth. However, if the box is able to flex to accommodate varying amounts of weight and momentum that are applied during shipping and handling, lower cost paperboard may be utilized, yet the carton will retain its integrity and uniformity throughout its useful life. This is especially desirable in the area of packing paper products, such as business forms, which tend to expand and contract over time and to settle after initial packing since voids are common in the depth dimension.
It is also necessary, if appropriate production speeds are to be achieved, to be able to produce cartons that solve the above mentioned problems with automated equipment, rather than requiring hand construction of the cartons.
According to the present invention, an apparatus is provided which effects construction of a carton which solves the above mentioned problems in a simple and effective manner. According to the present invention the expensive strapping equipment necessary for most commercial carton packaging systems is eliminated, the cost of materials for packaging are greatly reduced, and since the equipment utilized to effect packaging according to the invention is much less expensive with a much simpler construction, equipment maintenance costs are substantially reduced. For example, according to the present invention the apparatus for effecting packaging can be about one-fifth the cost of conventional strapping equipment, while the operating cost per thousand cartons is less than one-tenth, and almost no maintenance is required.
The invention comprises apparatus for packing and securing a cardboard carton. The carton utilized is preferably the carton disclosed in copending U.S. application Ser. No. 07/583,371 filed Sept. 17, 1990. According to one aspect of the invention, the apparatus comprises: Means for providing a compressive force to the lid so that the lid moves downwardly toward the carton body top edge. Means for moving the lid overlapping side panels away from the carton side walls, and applying adhesive thereto and/or to the cooperating portions of the carton side walls. And, means for maintaining compressive force on the lid and applying inward compressive force to the lid overlapping side panels to adhesively bond the overlapping side panels to the side walls.
The means for providing a compressive force preferably comprise a bottom conveyor, such as a plurality of rollers, and a top conveyor, such as a plurality of rollers that are slanting so as to provide a constantly decreasing height so as to effect gradual compression of the carton in the vertical dimension. A cam and applicator comprise the means for moving the lid overlapping side sections away from the carton side walls and applying glue to the carton side wall and/or the overlapping lid side sections. The means for maintaining the compressive force may comprise a plurality of vertical axis rollers biased horizontally into engagement with the side sections of the lid.
According to another aspect of the apparatus according to the invention, the apparatus comprises: Means for providing a compressive force to the carton lid so that the lid moves downwardly toward the carton body top edge. Means for attaching the lid overlapping side panels to the carton side walls; and means for maintaining compressive force on the lid and applying inward compressive force to the lid overlapping side panels coincident with action by the means for attaching the lid overlapping side panels to the carton side walls. The attaching means preferably comprises the adhesive applying means described above, but may also comprise means for spraying adhesive, or stapling or taping equipment.
According to another aspect of the apparatus of the invention, apparatus is provided comprising means for moving the carton lid overlapping side panels away from the carton side walls, and applying adhesive thereto and/or to the cooperating portions of the carton side walls, this means comprising a wedge shaped cam element for movement between the lid side panels and the carton body side wall disposed on each side of the carton to cam the side panel away from the carton wall, and an adhesive applicator for transferring adhesive to at least one of the interior of the side panel or exterior of the carton side wall as it moves therepast; and means for applying an inward compressive force to the lid overlapping side panels to adhesively bond the overlapping side panels to the side walls.
It is the primary object of the present invention to provide apparatus for effectively, simply, and inexpensively packing a carton and attaching the lid to the carton. This and other objects of the invention will become clear from an inspection of the description of the invention and from the appended claims.